Boring tool



March 11, 1941. B RAQ 2,234,451

BORING TOOL Filed Nov. 29, 1939 INVENTOR.

75W iia/miom ATTORNEY.

Patented-Mar. 11, 1941 UNITED STATES 2,234,451 BORING TOOL BernardRansome, Diablo, Calii'., assignor to Bansome Company, Emeryville,Calif., a corporation of California Application November 29, 1939,Serial No. 306,699-

3 Claims.

This invention relates to earth boring machines or apparatus of the typedisclosed in United States Patents No. 1,928,048 and No. 1,932,068, andespecially to boring tools to be used in con- 5 junction therewith.

The boring machine disclosed in the above mentioned patents isparticularly intended for boring or drilling holes of varying diametersunder streets, highways, railway tracks, etc., and

10 into embankments and hillsides where it is desired to collect anddrain away seepage water from underlying strata of clay or the like. Theholes when bored may serve as openings through which pipes are insertedfor connection with other pipes; or, where drainage is desired,perforated pipe is driven in to serve as permanent drainage ducts. Holesof this character are usually bored horizontally where pipe is to belaid, and at a slight upward angle where drainage is desired. The holesare often 100 feet or more in length, and considerable trouble isencountered in maintaining the hole straight, because of sagging orbending of the boring rod due to its own weight, at points between theboring bit and the boring machine whereby the rod or hit is driven orrotated. Also, in boring through sand, gravel and like formations, thereis a tendency for cavein and filling of the hole at points behind theboring bit, and when this occurs great difiiculty 3 is encountered inremoving the boring rod and bit. Again, in certain heavy clayformations, thev clay may ball around and behind the bit and materiallyretard operations.

The object of the present invention is generally to improve and simplifythe construction and operation of apparatus of the character described,and particularly to provide boring tools whereby the dimculties referredto are very materially reduced.

40 The boring machine and the tools employed are shown by way ofillustration in the accompanying drawing, in which Fig. 1 is a sideelevation, partially in section, showing the boring machine set up andthe hole started;

Fig. 2 is a vertical longitudinal section of a hole, showing the boringrod and tools in operative position within the hole;

Fig. 3 is a perspective view of one form of boring bit;

'Fig. 4 is an enlarged cross section of a boring or cutting blade;

Fig. 5 is a side elevation, partially in section, of a bit particularlyintended for rock and hard 55 formations;

Fig. 6 is a front view of the bit shown in Fig. 5;

Fig. 7 is a perspective view of a combination guide and supportingcoupling; and

Fig. 8 is a horizontal section of the type of bit shown in Figs. 5 and6. 5

Referring to the drawing in detail, and particularly to Figs. 1 and 2, Aindicates in general a boring machine of the type disclosed in UnitedStates Patent No. 1,932,068; B, the boring rod;

C, a combination guide and supporting coupling; 10

D, the main boring or reaming cutter; and E, a pilot bit. The boringmachine, briefly described, consists of a motor 2, driven by compressedair supplied by a hose 3 which is connected with any suitable source ofsupply. The motor, through reduction gears, drives or imparts rotarymovement to the boring rod and bits, and feeding or advance of theboring rod and bits is manually controlled through means of a lever 4.That is, the motor, together with the driving connections required, isslidable or longitudinally movable on the base generally indicated at 5.A pair of toothed rack bars 6 are disposed one on each side thereof, andpawls, not shown, actuated by the lever 4 engage the teeth of the rackbars so that when the operator pushes on the lever in one direction themotor, together with the boring rod and bits, is gradually advancedalong the base and into the hole as boring proceeds. Conversely, byreversing the pawls and the operation of the lever, the boring rods andbits may be retracted.

The boring rod employed is supplied in lengths of approximately 4 ft. 8in. It is provided with male and female screw connections at oppositeends to permit ready coupling or addition of rods as the hole lengthens,and it might further be stated that the rod is about two inches indiameter and has a small interior passage formed therein to permit waterunder high pressure to be introduced adjacent the cutting bits and towash away the cuttings.

Where hillsides or embankments adjoining highways, railway tracks, etc.,have a tendency to slide, it is usually due to an underlying stratum ofclay and flow of water which causes the overburden to slide. Anefiective method of stopping slides of this character is to drill orbore numerous holes into the hillside or bank at points where the waterstratum or flow is intersected, so as to permit free escape and drainagethereof. These holes are usually bored on an incline just suflicient topermit free flow of drainage water, and are often from to feet, or more,in length.

or gradually assume a greater and greater up- .ward incline. In" thepresent instance, an aux- "iliary coupling of the'type shown in Fig. 7is employed at suitable intervals. The coupling consists of a hub member8 of the same diameter as the drill rod. It has a water passage formedtherein, and male and female screw connections at opposite ends topermit it to be coupled between rod sections. A combination guide andsupporting sleeve l0 having a; diameter substantially that of the holeto be bored surrounds the hub 8 and is maintained concentric therewithby two or more spokes such as shown at 9. This sleeve may be 4, 6 ormore inches inwidth, and as such forms a support (see referencecharacter C in Fig. 1) which prevents sagging of the boring bar atpoints between the boring machine proper and the forward bits D and E.That is, couplings of the character shown in Fig. 7 may be interposedbetween every rod or between every second rod or so, as desired, andwhen they are employed, sagging is prevented and the direction of thehole, whether horizontal or slightly inclined, may be maintained andassured.

In drilling or boring through certain'formations such as sand, graveland the like, and in fact in any type of formation, it must beremembered that water under high pressure, for instance 100# gauge ormore, is continuously being discharged adjacent the boring bits, asindicated at 20 in Fig. 5, to keep the bit cool, to soften theformation, and particularly to carry away the cuttings. A continuouswater flow is thus maintained through the hole, and due thereto, andalso due to sand and gravel-like formations, caving of the hole behindthe bits D and ill will sometimes take place; and when this oc'curs itis almost impossible to remove the boring rod and bits.

. Also, it may be stated that due to the fact that the drill rod iscoupled by screw connections, rotation of the rod and bits must alwaysbe in one direction, In this direction the bits will cut and advance. Ifthe direction were reversed by the motor 2, the couplings would unscrew,and removal of the rod would be substantially impossible. Where cavingorclogging of the hole behind the forward bits takes place, little ifany trouble is encountered in the present instance,

as bits of the character shown in Figs. 3 and 5 are employed. I

In rock or hard formations, the bit shown in Figs. 5, 6 and 8 is used.It consists of a hub member Illa surrounded by a sleeve ll supported byspokes l2. To these spokes are bolted or otherwise secured cutting bitsI: of the type P rticularly shown in Fig. 8. These bits cut duringforward advance. Behind them are one or more angularly disposed cuttingblades it. They are pitched in a direction opposite to feed advance,

and if the hole is caved or filled in behind the hits, the rod and bitsmay be rotated in the same direction, but the pull on the lever l isreversed, and as the rod and bits are being pulled out, the blades 14will cut their way. out, as they are set on an angle and pitch to do so.Thus the bit shown in Fig. 5 will not only cut its way inwardly when therotation is in 'one direction, but it will also cut its way out againwith the same direction of rotation, due to the reverse angle or pitchof the blades l 4.

In softer formations, such as sand, gravel, clay and the like, the typeof coupling shown in Fig. 3 is employed. This again consists of a hubmember II, a surrounding sleeve ll supported by'spokes l1, and cuttingblades such as shown at I0 and is. The forward blades cut'during forwardmovement of the rod and bits, while the blades ll, which are set on areverse angle to the front blades, cut during removal or extraction ofthe rod and bits.

Where a hole of considerable length or depth is being drilled, bits suchas shown in Fig. 3

may be interposed at spaced intervals along the boring rod as asubstitute for the coupling shown.

in Fig. '1. Thus they function not only as a support and guide for theboring rod, to prevent sagging or'bending of it, butthey also aid inextraction of the rods and bits where caving has typeshown in eitherFig. 3 or Fig. 5, depending upon the character of the formation. To thisextent the type of cutter indicated at D might be deemed a reamer, as itis preceded by the pilot bit E. The final size of the hole is thus cut,and whilethe hole of final diameter is being cut the main cutter D isguided not only by the pilot bit E but also by the sleeves l6 placed onthe rod at suitable intervals.

From the above descriptionit should appear obvious that the troublesheretofore encountered in boring holes of this character have beensubstantially eliminated.

Having thus described and illustrated my invention, what! claim anddesire to secure by Letters Patent is:

1. a rotary boring tool of the character described adapted for rotationin one direction only, said tool having a central elongated hub, a pairoi radially xtending substantially diametrically opposed cutting bladessecured to the front end of the hub and disposed on an angle to cut whenthe boring tool is being advanced, a similar pair of cutting bladessecured to the rear end of the hub, but with the angle reversed so as tocut when the tool is being retracted. a cylindrical sleeve disposedintermediate the front and rear cutting blades and spaced from both, andspokes on the hub securing said sleeve in a position concentric with thehub. I

2. A rotary boring tool of the character described adapted for rotationin one direction only, said tool having a central elongated hub, a pairof radially extending substantially diametrically opposed spokes securedto the hub adjacent the forward end thereof, a cylindrical sleeveconcentric with the hub and secured to therefrom, said blades beingdisposed on an angle throughmrt their 1 to cut during retraction of thetool.

3. A rotary boring'tool of the character described adapted or rotationin one direction only, said tool having a central elongated hub, a pairof radially extending diametrical- 1y opposed'spokes secured to thehub-adjacent the forward end thereof, a cylindrical sleeve concentricwith the hub and secured to the spokes, a detachable cutting bladesecured to each spoke, said blades extending radially from the hub andbeing sumciently long to project beyond the outer periphery of thesleeve, to cut a bore slightly larger than the diameter 0! the sleeve,and said bladm being substantially V-shaped in crosssection throughouttheir length, with the apex of the V pointing in' the directionotrotation of the boring tool, to out during'advance of the tool, a pairof radially extendingsulmtantially diametrically opposed cut-ting bladessecured to the hub behind the sleeve and spaced therefrom, said bladesbeing disposed on an angle throughout their length to cut duringretraction of the tool, a central passage formed in the hub of the tooland adapted to be connected with a. source of water under pressure, anda pair of radial discharge passages formed in the hub in communicationwith the central passage, said discharge passages directing water from apoint between the inner ends 01' the detachable cutting blades andtowards the face upon which the blades are operating.

BERNARD RANSOME.

